Coherent LIDAR system comprising optical antenna array

Abstract

The invention relates to a coherent LIDAR system comprising an optical antenna array. A light detection and ranging (LIDAR) transceiver includes an optical antenna array and an optical switch. Some of the optical antenna arrays include a plurality of optical antennas and an optical splitter coupled to the optical antennas. The optical splitter may include a plurality of passive optical splitters. The optical splitter provides a portion of the input signal to the optical antenna. The optical switch is configured to selectively provide an input signal to at least one of the plurality of optical antenna arrays. The optical switch enables addressable field-of-view scanning by selectively providing input signals to a plurality of antenna arrays one array at a time.

Description

[0001] This application is a divisional application of the application with PCT application number PCT / US2021 / 065133, international filing date of December 23, 2021, Chinese application number 202180085639.2, and invention title "Coherent LIDAR System Including an Optical Antenna Array", which entered the Chinese national phase on June 19, 2023.

[0002] Cross-reference to Related Applications

[0003] This application claims the priority of U.S. Non-Provisional Application No. 17 / 558,476 filed on December 21, 2021, which claims the priority of U.S. Provisional Application No. 63 / 129,847 filed on December 23, 2020, and they are incorporated herein by reference. Technical Field

[0004] The present disclosure generally relates to coherent optical detection and ranging (LIDAR), and more particularly to an optical antenna architecture for coherent LIDAR. Background Art

[0005] Frequency-modulated continuous-wave (FMCW) LIDAR directly measures the distance and velocity of an object by aiming a frequency-modulated collimated light beam at the target. Both the distance and velocity information of the target can be derived from the FMCW LIDAR signal. Designs and techniques for improving the accuracy of LIDAR signals are desirable.

[0006] The motor vehicle industry is currently developing autonomous features for controlling vehicles in certain situations. According to the SAE International Standard J3016, there are six levels of autonomy, ranging from level 0 (no autonomy) to level 5 (the vehicle can operate in all situations without operator input). Vehicles with autonomous features use sensors to sense the environment through which the vehicle is navigating. Obtaining and processing data from the sensors allows the vehicle to navigate in its environment. Autonomous driving vehicles may include one or more LIDAR devices for sensing their environment. Summary of the Invention

[0007] Embodiments of the present disclosure include a transceiver for an optical detection and ranging (LIDAR) sensor system. The transceiver includes a plurality of optical antenna arrays and an optical switch. At least two of the plurality of optical antenna arrays include a plurality of optical antennas and a beam splitter coupled to the plurality of optical antennas. The optical switch is coupled to the plurality of optical antenna arrays. The optical switch is configured to selectively provide an input signal to at least one of the plurality of optical antenna arrays.

[0008] In an embodiment, the input signal is a modulated laser signal. The optical switch includes an active beam splitter that selectively couples the modulated laser signal to only one of the plurality of optical antenna arrays.

[0009] In an embodiment, the input signal is a frequency-modulated continuous-wave (FMCW) laser signal. The optical switch includes an active splitter that selectively couples the FMCW laser signal to only one of a plurality of optical antenna arrays.

[0010] In an embodiment, the optical switch optically couples the input signal to at least one of the plurality of optical antenna arrays one at a time during a scan period of the transceiver.

[0011] In an embodiment, the splitter includes a plurality of passive splitters configured to split a portion of the input signal among a plurality of optical antennas in a selected one of the plurality of optical antenna arrays.

[0012] In an embodiment, the splitter is configured to enable concurrent transmission of input signals from a plurality of optical antennas.

[0013] In an embodiment, the plurality of optical antennas are arranged in a one-dimensional pattern or a two-dimensional pattern.

[0014] In an embodiment, at least one of the plurality of optical antenna arrays includes an optical pixel. The optical pixel includes at least one of the plurality of optical antennas and an optical combiner. The optical combiner is coupled to at least one of the plurality of optical antennas. The optical combiner is configured to receive a local oscillator signal and a return LIDAR signal from at least one of the plurality of optical antennas. The optical combiner is configured to provide a combined output signal.

[0015] In an embodiment, the optical pixel further includes a plurality of photodiodes configured to convert the combined output signal into an electrical signal representative of a LIDAR beat note.

[0016] In an embodiment, the transceiver for a LIDAR sensor system according to claim 1 further includes a local oscillator configured to provide a plurality of local oscillator signals to the plurality of optical antenna arrays.

[0017] In an embodiment, the local oscillator includes a plurality of splitters configured to provide a plurality of oscillator signals to the plurality of optical antenna arrays, and includes a second optical switch coupled to the plurality of splitters and configured to selectively provide a portion of the input signal to at least one of the plurality of splitters.

[0018] In an embodiment, at least one of the plurality of splitters includes a plurality of passive splitters configured to split a portion of the input signal among a plurality of optical antennas in a selected one of the plurality of optical antenna arrays.

[0019] In an embodiment, at least two of the plurality of optical antenna arrays include output signal buses. A plurality of optical antennas of a first optical antenna array among the plurality of optical antenna arrays share an output signal bus with a second optical antenna array among the plurality of optical antenna arrays.

[0020] In an embodiment, the output signal bus includes electrical signal lines for in-phase signals and quadrature signals from each of the plurality of optical antennas.

[0021] Embodiments of the present disclosure include a light detection and ranging (LIDAR) sensor system. The LIDAR sensor system includes a light source and a transceiver. The light source is configured to generate an input signal. The transceiver is coupled to the light source to receive the input signal. The transceiver includes a plurality of optical antenna arrays and an optical switch. At least two of the plurality of optical antenna arrays include a plurality of optical antennas and a beam splitter coupled to the plurality of optical antennas. The optical switch is coupled to the plurality of optical antenna arrays. The optical switch is configured to selectively provide the input signal to at least one of the plurality of optical antenna arrays.

[0022] In an embodiment, the LIDAR sensor system further includes a lens. The transceiver is optically coupled to the lens to provide solid-state scanning of a field of view block of the lens.

[0023] In an embodiment, the LIDAR sensor system further includes a processing engine, which is configured to receive a LIDAR return signal from the transceiver and is configured to generate a LIDAR data frame based on the LIDAR return signal.

[0024] Embodiments of the present disclosure include an autonomous vehicle. The autonomous vehicle includes a light detection and ranging (LIDAR) sensor. The LIDAR sensor includes a light source configured to generate an input signal and a transceiver. The transceiver is coupled to the light source to receive the input signal. The transceiver includes a plurality of optical antenna arrays and an optical switch. At least two of the plurality of optical antenna arrays include a plurality of optical antennas and a beam splitter coupled to the plurality of optical antennas. The optical switch is coupled to the plurality of optical antenna arrays. The optical switch is configured to selectively provide the input signal to at least one of the plurality of optical antenna arrays.

[0025] In an embodiment, the autonomous vehicle further includes a lens. The transceiver is optically coupled to the lens to provide horizontal scanning of a block of the operating environment of the autonomous vehicle.

[0026] In an embodiment, the autonomous vehicle further includes a processing engine, which is configured to receive a LIDAR return signal from the transceiver and is configured to generate a point cloud representation of the operating environment of the autonomous vehicle based at least in part on the LIDAR return signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, in which like reference numerals refer to like parts throughout the various views unless otherwise specified.

[0028] Figure 1 A diagram of a chip for a LIDAR sensor according to an embodiment of the present disclosure.

[0029] Figures 2A to 2D Diagrams of various embodiments of coherent pixels according to an embodiment of the present disclosure.

[0030] Figure 3 A diagram of a chip for a LIDAR sensor according to an embodiment of the present disclosure.

[0031] Figures 4A to 4B Diagrams of various embodiments of coherent pixels according to an embodiment of the present disclosure.

[0032] Figures 5A to 5C Diagrams of various embodiments of an optical switch that can be used in a LIDAR system according to an embodiment of the present disclosure.

[0033] Figure 6 A diagram of a LIDAR system according to an embodiment of the present disclosure.

[0034] Figures 7A to 7B A diagram of an electrical wiring scheme for routing output signals according to an embodiment of the present disclosure.

[0035] Figure 8 A diagram of coherent pixels according to an embodiment of the present invention.

[0036] Figure 9 A system diagram of a LIDAR system based on a switchable coherent pixel array according to an embodiment of the present disclosure.

[0037] Figure 10A A diagram of an autonomous vehicle including an example sensor array according to an embodiment of the present disclosure.

[0038] Figure 10B A top view of an autonomous vehicle including an example sensor array according to an embodiment of the present disclosure.

[0039] Figure 10C A diagram of an example vehicle control system including sensors, a powertrain, and a control system according to an embodiment of the present disclosure. Detailed Description

[0040] This document describes embodiments of a coherent optical detection and ranging (LIDAR) system. In the following description, numerous specific details are set forth to provide a thorough understanding of the implementations. However, those skilled in the relevant art will recognize that the techniques described herein can be practiced without one or more of the specific details or with the use of other methods, components, materials, etc. In other instances, well-known structures, materials, or operations have not been shown or described in detail to avoid obscuring certain aspects.

[0041] References to "one embodiment" or "an embodiment" throughout this specification mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the present invention. Thus, the phrases "in one embodiment" or "in an embodiment" that appear throughout this specification do not necessarily all refer to the same embodiment. Additionally, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0042] Throughout this specification, several technical terms are used. These terms have their ordinary meanings in the fields from which they are derived, unless specifically defined herein or the context in which they are used clearly implies otherwise. For the purposes of this disclosure, the term "autonomous vehicle" includes vehicles having autonomous features at any level of autonomy as defined by SAE International standard J3016.

[0043] Discussed herein is a scalable and switchable optical antenna array architecture that, when combined with a lens, forms a real-time addressable focal plane array for solid-state beam steering in a coherent LIDAR system.

[0044] Traditional LIDAR systems rely on mechanical moving parts to control the direction of the laser beam. Thus, for many applications such as motor vehicles and robots, they can be bulky, costly, and unreliable. The disclosed LIDAR system is a solid-state LIDAR system that overcomes these problems by eliminating or reducing the mechanical moving parts used to control the direction of the beam for LIDAR operation.

[0045] Coherent LIDAR systems include modulated, continuous wave (CW), and other types of LIDAR systems. Modulated LIDAR systems include frequency-modulated continuous wave (FMCW) LIDAR systems and phase-shift keying (PSK) systems, among others. Coherent LIDAR systems can directly measure the distance and velocity of an object by directing a frequency-modulated or CW collimated beam onto the object. The light reflected from the object is combined with a tapped version of the beam. Once corrected for a possible Doppler frequency shift that may be based on a second measurement, the frequency of the resulting beat is proportional to the distance of the object from the LIDAR system. These two measurements (which may be made simultaneously or non-simultaneously) provide both range and velocity information.

[0046] One consideration in designing solid-state beam steering technology for a LIDAR system is the complexity of the control circuitry. Reducing complexity has numerous advantages in terms of cost, reliability, and scalability.

[0047] Another consideration in the design of solid-state beam steering technology is the scan pattern, which is the order of illumination of one or more laser scenes. If the parallel optical channels (e.g., of an optical antenna) can be spatially lumped together, then smaller contiguous blocks within the full field of view of the LIDAR system can be dynamically addressed and adjusted according to the needs of the application. The ability to dynamically address blocks or portions of the field of view can advantageously reduce artifacts that can appear in the point cloud generated from the scan. Additionally, the concurrent operation of adjacent / closely positioned groups of optical antennas can occur with low latency, which can provide improved resolution and improved object recognition over traditional scanning techniques.

[0048] The disclosed coherent LIDAR system can be a modulated (e.g., FMCW) LIDAR system, a CW LIDAR system, or another coherent LIDAR system configured to determine depth information (e.g., distance, velocity, acceleration of one or more objects) of the field of view of the system. The coherent LIDAR system can include a switchable coherent pixel array (SCPA) on a LIDAR chip (e.g., a photonic integrated circuit). The LIDAR chip can include one or more transceivers. The transceiver can include an optical antenna array and an optical switch. The optical antenna array includes groups (sub-arrays) of optical antennas and a beam splitter coupled to the optical antennas. The beam splitter provides a portion of the input signal to each optical antenna. The input signal can be an electrical signal, an electro-optical signal, or an optical signal. The optical switch is configured to selectively provide the input signal to at least one of the plurality of optical antenna arrays as part of a scanning operation. The optical switch achieves an addressable field of view scan by selectively providing the input signal to the plurality of antenna arrays (one array at a time). Each optical antenna can be part of a coherent pixel that includes an optical antenna, an optical combiner, a beam splitter, and / or a photodiode. Thus, a sub-array or group of coherent pixels can include a sub-array or group of optical antennas.

[0049] The coherent LIDAR system can be configured to control the direction of light (e.g., a beam, a laser beam) emitted from the LIDAR system in at least one dimension. In some embodiments, the optical antennas are arranged in a two-dimensional layout such that the LIDAR system can control the direction of light in two dimensions. The ability to control the direction of light without moving parts can reduce form factor, cost, and reliability issues present in many traditional mechanically driven LIDAR systems.

[0050] The devices and systems of the optical antenna architecture for coherent LIDAR transceivers in this disclosure implement a solid-state addressable field of view and a scalable focal plane array, which can be used, for example, in autonomous vehicles. These and other embodiments are described in more detail Figures 1 to 10C described in more detail.

[0051] Figure 1 A diagram of a chip of a LIDAR sensor 100 according to an embodiment of the present disclosure is shown. According to various embodiments, the LIDAR sensor 100 can be a coherent LIDAR system, such as a part of a modulated LIDAR system, a CW LIDAR system, an FMCW LIDAR system, or another coherent LIDAR system. According to an embodiment, the LIDAR sensor 100 is a switchable coherent pixel array (SCPA) LIDAR sensor on a chip, which includes an optical antenna configured to concurrently scan a portion of the field of view of the LIDAR system. The LIDAR sensor 100 can be a photonic integrated circuit and can be configured to perform block scanning with beams having a dense pitch. Advantageously, the block scanning environment can reduce artifacts that may appear in the point cloud generated during the scanning operation. Additionally, the concurrent operation of adjacent / closely positioned optical antenna groups supports low-latency operation, thereby providing improved resolution and improved object recognition in multiple applications, such as autonomous vehicle operation.

[0052] According to an embodiment, the LIDAR sensor 100 includes an input port 102 coupled to provide an input signal to a transceiver 104. The input signal can be an electrical signal, an electro-optical signal, or an optical signal. The input signal can be a CW laser signal. The input signal can be a modulated laser signal. The input signal can be an FMCW laser signal. The transceiver 104 includes an optical switch 106 and a plurality of optical antenna arrays 110 configured to be able to perform block scanning of the environment with the LIDAR system. The optical switch 106 receives the input signal from the input port 102 through a communication channel 108 (e.g., a waveguide). The optical switch 106 selectively distributes at least a portion of the input signal to the optical antenna arrays 110, one at a time. According to an embodiment, the optical switch 106 is an active switch including M output channels and can be implemented as a silicon nitride switch with high power handling capabilities.

[0053] In one embodiment, the optical switch 106 routes the input signal from the input port 102 to each optical antenna array 110, one at a time during a scanning operation (e.g., during each scan of the field of view). Each of the optical antenna arrays 110 is a building block or group of components that routes a portion of the input signal to optical antenna groups (sub-arrays) for concurrent transmission of the input signal. The components of each optical antenna array 110 are also configured to receive the returned LIDAR signal and convert the returned LIDAR signal from an optical signal into one or more electrical signals.

[0054] As shown, according to an embodiment, the transceiver 104 includes a plurality of optical antenna arrays 110 (for clarity, only one array is highlighted in the dashed box). Each optical antenna array 110 includes a splitter 112 coupled to the optical switch 106 via a communication channel 114 (e.g., a waveguide). Each optical antenna array 110 includes a group of coherent pixels 116 (e.g., a sub-array) that consists of a number (e.g., 8, 50, 100, etc.) of individual coherent pixels 118. Each of the individual coherent pixels 118 is spatially located near other individual coherent pixels 118 in a one-dimensional pattern (e.g., a line) or in a two-dimensional pattern (e.g., a rectangle, another shape, or in a non-uniform distribution).

[0055] The group of coherent pixels 116 is coupled to the splitter 112 via a plurality of communication channels 120 (e.g., waveguides). According to an embodiment, the splitter 112 includes a passive splitter network that is configured to evenly distribute the input signal from the communication channel 114 to the communication channels 120.

[0056] In an embodiment, the optical switch 106 can be selected from M optical antenna arrays 110, and the splitter 112 splits the input signal into N communication channels 120, where the number N corresponds to the number of individual coherent pixels 118 in the group of coherent pixels 116. N is also the number of transmitter and receiver channels, and thus N can also define the total number of concurrent (approximately simultaneous) measurements that can be made by the group of coherent pixels 116. The aggregation of the optical antennas 110 can be placed under a lens to form a solid-state focal plane array. Since the parallel channels are spatially grouped in this array, a smaller block within the full field of view of the focal plane array can be illuminated, allowing for dynamic addressing of the full field of view.

[0057] One advantage of the architecture of the transceiver 104 is that the use of the optical switch 106 reduces the number of optical ports for operation. The reduction in optical ports results in a simpler and smaller silicon footprint in the optical path between the input port 102 and the optical antennas of the individual coherent pixels 118 (shown in Figures 2A-2D ).

[0058] Although a single transceiver 104 is shown, according to various embodiments, the LIDAR sensor 100 may include multiple transceivers 104 coupled to other optical ports or coupled to the input port 102.

[0059] Figures 2A-2D Illustrated are various embodiments of coherent pixels (e.g., individual coherent pixels 118 as shown in Figure 1 ) that may be utilized in the LIDAR sensor 100 according to embodiments of the present disclosure. The coherent pixels may be configured to (1) split an input signal into a local oscillator signal and a transmission signal, (2) couple the transmission signal to free space, (3) couple a return signal back to the coherent pixel, and / or (4) mix the local oscillator signal and the return signal.

[0060] Figure 2A and Figure 2B Illustrated are coherent pixel 220 and coherent pixel 230 according to embodiments of the present disclosure. Coherent pixel 220 includes optical antenna 200, optical combiner 201, and optical splitter 202. Coherent pixel 220 receives an optical signal (e.g., a modulated laser signal, a CW laser signal, an FMCW laser signal, etc.) at input port 203. Optical splitter 202 is coupled between input port 203 and optical antenna 200. Optical splitter 202 may be a bidirectional 2x2 optical splitter configured to split an input signal received on input port 203 into an antenna port 205 and a local oscillator port 206. Antenna port 205 is coupled to optical antenna 200. Antenna port 205 is configured to provide a transmission signal to optical antenna 200 and is configured to receive a return signal from optical antenna 200.

[0061] According to an embodiment, optical antenna 200 is a device that emits light from an on-chip waveguide into free space and / or couples light from free space into an on-chip waveguide. Optical antenna 200 may be implemented as a grating coupler, an edge coupler, an integrated reflector, or any spot size converter. Optical antenna 200 may be polarization sensitive, having a much higher emission / coupling efficiency for light having a particular polarization (e.g., transverse electric (TE) or transverse magnetic (TM)). Optical antenna 200 may be reciprocal and thus may collect a return signal (e.g., a reflected beam) from an object being measured (e.g., an object in the environment). Optical antenna 200 provides the return signal back to antenna port 205 of optical splitter 202. Optical splitter 202 may split the return signal between input port 203 and return signal port 204, or may be configured to provide only the return signal to return signal port 204. Optical splitter 202 may be configured as a "pseudo circulator" with co-located transmitter and receiver.

[0062] The optical combiner 201 is configured to mix the local oscillator signal with the return signal. The optical combiner 201 mixes the return signal from the return signal port 204 and the local oscillator signal from the local oscillator port 206 for coherent detection. The optical combiner 201 is an optical mixer, which can be a balanced 2x2 optical mixer.

[0063] The coherent pixel 220 includes a pair of photodiodes 207, which are configured to convert an optical signal into an electrical signal for beat detection. The coherent pixel 220 may be referred to as a balanced photodiode (BPD) coherent pixel.

[0064] Using the optical splitter 202 as a "pseudo-circulator" can eliminate the need for a discrete circulator for each individual pixel, which is impractical for large-scale arrays with hundreds of pixels. Thus, the implementation of the coherent pixel 220 can significantly reduce cost and form factor. For example, the return signal can be split between the input port 203 and the return signal port 204, with the latter being used for coherent detection.

[0065] According to an embodiment, the coherent pixel 230 includes a hybrid optical combiner 209 and includes two pairs of photodiodes 207 to convert the return signal and the local oscillator signal into electrical signals for beat detection. According to an embodiment, the coherent pixel 230 uses the hybrid optical combiner 209 to provide an in-phase output signal RX_I and a quadrature output signal RX_Q. The in-phase output signal RX_I and the quadrature output signal RX_Q can be used to resolve velocity-distance ambiguities and / or implement advanced digital signal processing (DSP) algorithms in an FMCW LIDAR system.

[0066] Figure 2C and Figure 2D Illustrated are the coherent pixel 240 and the coherent pixel 250 according to an embodiment of the present disclosure. The coherent pixels 240 and 250 include polarization splitting antennas that can simplify the design of the optical splitters used in the coherent pixels.

[0067] According to an embodiment, the coherent pixel 240 includes a beam splitter 212, a polarization splitting antenna 210, an optical combiner 201, and a photodiode pair 207. An input signal is received at the input port 203. The beam splitter 212 may include an input port coupled to the input port 203, an antenna port 215, and a local oscillator port 214. A portion of the input signal routed to the antenna port 215 is directly transmitted from the chip using the polarization splitting antenna 210 having a certain polarization (e.g., TM). The polarization splitting antenna 210 collects the return signal (reflected beam) from the object under measurement. The polarization splitting antenna 210 couples the orthogonal polarization (e.g., TE) to the antenna output port 213 (e.g., waveguide) and directly transmits the orthogonal polarization return signal to the optical combiner 201. In this embodiment, the return signal received by the polarization splitting antenna 210 is not further split by any additional beam splitter or "pseudo circulator".

[0068] The optical combiner 201 optically mixes the received return signal from the antenna output port 213 with a portion of the optical signal from the local oscillator port 214 for coherent detection. The photodiode pair 207 converts the combined / mixed optical signal into an electrical signal for beat detection.

[0069] The coherent pixel 250 includes a hybrid optical combiner 209 and a polarization splitting antenna 210, and two photodiode pairs 207 convert the optical signal into an in-phase output signal RX_I and a quadrature output signal RX_Q, which are electrical signals available for beat detection.

[0070] The designs of the coherent pixels 240 and 250 implement an efficient integrated circulator for each coherent pixel and can achieve a single-chip monostatic FMCW LIDAR with ultra-high sensitivity.

[0071] Figure 3 A diagram of a chip of a LIDAR sensor 300 configured to selectively route a local oscillator signal to a coherent pixel according to an embodiment of the present disclosure. The LIDAR sensor 300 may include many features of the LIDAR sensor 100 ( Figure 1 as shown). The LIDAR sensor 300 reduces the components from the coherent pixel by directly providing an external local oscillator signal, rather than having the coherent pixel split its own portion of the input signal received at the input port 102. Compared with the coherent pixel being configured to generate its own local oscillator signal, the LIDAR sensor 300 is configured to provide a stronger local oscillator signal to the coherent pixel.

[0072] According to an embodiment, the LIDAR sensor 300 includes a local oscillator network 302 coupled to a splitter 304 to receive a portion of the input signal as a local oscillator signal. The local oscillator network 302 (e.g., a switch tree) includes an optical switch 306 configured to selectively provide the local oscillator signal to one of a plurality of splitters 308. Each splitter 308 is coupled to the optical switch 306 by a communication channel 310 (e.g., a waveguide). According to an embodiment, the splitter 308 is coupled to a group of coherent pixels 116 by a communication channel 312. The optical switch 306 can be similar to the optical switch 106 and can be configured to provide the local oscillator signal to a particular group of coherent pixels 116 while the optical switch 106 provides the input signal to the particular group of coherent pixels 116. The optical splitter 308 can be similar to the splitter 112 and can include a plurality of passive splitter components.

[0073] Figure 4A and Figure 4B Illustrated are coherent pixels 400 and 410 according to embodiments of the present disclosure, which are configured to receive an external local oscillator signal, for example, from the local oscillator network 302 ( Figure 3 as shown). The coherent pixels 400 and 410 are configured to receive the local oscillator signal at a local oscillator port 402. According to an embodiment, the coherent pixels 400 and 410 include features similar to the coherent pixels 240 and 250 (shown in Figure 2C and Figure 2D respectively).

[0074] Figures 5A-5C Illustrated are various embodiments of an optical switch that can be used in any LIDAR system of the present disclosure. Figure 5A Illustrated is an optical switch 506 that can be an embodiment of the optical switch 106 and / or the optical switch 306. According to an embodiment, the optical switch 506 is a binary tree switch network having a plurality of individual switch units 501. The individual switch unit 501 includes a splitter 500 configured to feed two optical phase shifters 502, and the two optical phase shifters 502 use control signals 503 and 504 to tune the phase of each arm. The electrical control of the optical switch 506 can be a push-pull manner using two controls or can be a single-sided manner using a single control. In an embodiment, an optical combiner 505 is used to recombine the signals passing through the optical phase shifters 502. Based on the operation of the control signals 503 and 504, constructive interference or destructive interference occurs and causes the light to switch between two outputs. The optical phase shifter 502 can be implemented as a thermo-optic phase shifter and / or an electro-optic phase shifter.

[0075] Figure 5BIllustrated is an optical switch 520 implemented as an array of microring resonators (MRRs) 510. When the resonance frequency of the device aligns with the laser wavelength, each MRR 510 picks up an optical signal from the main bus waveguide 512. According to an embodiment, electrical control signals (e.g., Ctrl 0, Ctrl 1, Ctrl 3, Ctrl M) can be used to set the resonance of each MRR 510 in the array and thus select the output port 511 through which a coherent optical signal (e.g., an FMCW optical signal) is transmitted and received.

[0076] Figure 5C Illustrated is an optical switch 530 implemented as an array of microelectromechanical systems (MEMS) switches 515. According to an embodiment, each MEMS switch 515 is configured to control the direction of an optical signal from the main bus waveguide 512 and thus select the output port (e.g., Out 1, Out 2, Out 3, Out M) through which the optical signal is transmitted and received.

[0077] Figure 6 Illustrated is a LIDAR system 600 that incorporates a LIDAR sensor 100 to form an addressable focal plane array. Each optical antenna array 110 includes N coherent pixels that concurrently transmit input signals when a particular one of the optical antenna arrays 110 is selected. The transmission of the input signals from the coherent pixels through the lens system 607 becomes a laser beam 608. Each of the optical antenna arrays 110 scans a portion of the field of view of the lens system 607, which gives the LIDAR system 600 a solid-state addressable field of view. When the output of the optical switch 106 selects a particular one of the optical antenna arrays 110, each of the N coherent pixels simultaneously illuminates the lens system 607, which collimates the incident light into N outgoing laser beams 608 that propagate at slightly different angles. Based on the coherent pixel pitch in the LIDAR sensor 100 and based on the characteristics of the lens system 607, the outgoing laser beams 608 propagate at slightly different angles. As a result, each optical antenna array 110 illuminates a small portion of the complete field of view of the focal plane array system.

[0078] Figure 7AIllustrated is an electrical wiring scheme 700 for routing in-phase (I) and quadrature (Q) signals out of an optical antenna array 110 according to an embodiment of the present disclosure, each optical antenna array including N coherent pixels. In the illustrated example, every 8th coherent pixel is connected together on a bus 702, and a total of 2*N buses lead out from the switch (N for in-phase signals and N for quadrature signals). According to this wiring scheme, according to an embodiment, the bus 702 (including channels RX_1, RX_2, RX_3, ……, RX_N) is used by one optical antenna array 110 at a time because the optical switch 106 only selects a particular one of the optical antenna arrays 110 at a time.

[0079] Figure 7B Illustrated is an electrical wiring scheme 710 for routing in-phase (I) and quadrature (Q) signals out of an optical antenna array 110 according to an embodiment of the present disclosure, each optical antenna array 110 including N coherent pixels. In the illustrated example, the optical antenna array 110 is divided into two (or more) smaller groups, which are read out on buses 712 and 714. Bus 712 includes output channels RX1_1, RX1_2, RX1_3, ……, RX1_N, and bus 714 includes output channels RX2_1, RX2_2, RX2_3, ……, RX2_N. Then every 8th coherent pixel within these smaller groups is connected to a common bus (e.g., bus 712 or bus 714) and routed out of the array. In this example, if there are P subgroups of coherent pixels, there are a total of 2*P*N signal buses leaving the optical antenna array. These 2*P*N buses can then be combined, for example, using an electrical switch to reduce the total amount of signal lines.

[0080] Figure 8A diagram illustrating a coherent pixel 813 that utilizes two polarizations of light to improve the performance of an FMCW LIDAR system, in accordance with one or more embodiments of the present disclosure. Input light 801 from a laser enters the coherent pixel 813 and is split by an X / (1-X) splitter 802 (also referred to as splitter 802). X% of the light, which constitutes the TX signal, exits the top port of the splitter 802, and (1-X)% of the light, which constitutes the local oscillator (LO) signal, exits the bottom port of the splitter 802. The TX signal enters a polarization assembly 820. As shown, the polarization assembly 820 includes a polarization beam splitter 803 and a polarization-insensitive free-space coupler 804. However, in other embodiments, the polarization beam splitter 803 and the polarization-insensitive free-space coupler 804 may be replaced with a single polarization-splitting vertical chip-to-free-space coupler. The polarization beam splitter 803 (also referred to as a polarizer), separates transverse electric (TE) and transverse magnetic (TM) polarized light. Since the TX signal light is TE polarized, this light is coupled to the top port on the right side of the polarization beam splitter 803. The TM polarized light exits through the bottom port on the right side of the polarization beam splitter 803. The TX signal that exits the polarization beam splitter 803 enters the polarization-insensitive free-space coupler 804, which generates a free-space beam 805 with a linear polarization that matches the TE field of the coherent pixel 813. The polarization-insensitive free-space coupler 804 is an example of an optical antenna. For example, the polarization-insensitive free-space coupler 804 may be a vertical grating, an edge coupler (such as an inverted taper waveguide), or an angled reflector.

[0081] The free-space beam 805 propagates through a quarter-wave plate 806 that converts the linearly polarized beam into a circularly polarized beam 807. The now circularly polarized light 807 propagates a distance that delays the light relative to the LO signal. The beam reflects from the target surface 808, generating a reflected beam 809 (the return signal). Depending on the surface characteristics, the reflected beam may maintain its circular polarization or its polarization may become randomized. The reflected beam 809 propagates back through free space and the quarter-wave plate 806. If the reflected beam 809 maintains its circular polarization, the transmitted beam 810 will have a TM polarization (relative to the original transmitted and received coherent pixels 813). If the reflected beam 809 has a randomized polarization, the transmitted beam 810 will have a randomized polarization. The transmitted beam 810 couples back into the coherent pixel 813 and propagates back to the top right port of the polarization beam splitter 803. If the received beam is TM polarized, all of the light will be coupled to the bottom left port of the polarization beam splitter 803. If the received beam is randomly polarized, then nominally half of the optical power will be coupled to the bottom left port. The light coupled to the bottom left port of the polarization beam splitter 803 enters a dual-input power optical mixer 811 that mixes the delayed received signal with the LO signal. The optical mixer 811 generates one or more electrical signals 812 that are interpreted by the FMCW LIDAR system. Removing the quarter-wave plate may affect the system performance of a polarization-maintaining target surface, but does not affect the basic principle of the idea.

[0082] The polarization assembly 820 may be configured to form a transmitted signal; polarize the transmitted signal to have a first polarization; polarize the reflected signal (via in-coupling within 804) based on a second polarization orthogonal to the first polarization to form a return signal; and couple the return signal to a second waveguide for optical detection (e.g., towards 811).

[0083] The coherent pixel 813 may be, for example, the coherent pixel 118 ( Figure 1 shown). The coherent pixel 813 may also be an embodiment of the coherent pixel described above with reference to Figures 2A-2B description. For example, the beam splitter 202 may be replaced with an X / (1-X) beam splitter 802 and a polarization beam splitter 803, and the optical antenna 200 may be replaced with a polarization-insensitive free-space coupler 804.

[0084] Figure 9FIG. illustrates a system diagram of an FMCW LIDAR system 900 based on a switchable coherent pixel array (SCPA) according to one or more embodiments of the present disclosure, as a specific example of a coherent LIDAR system. The scanner module 901 includes an SCPA LIDAR chip 905 having single or multiple FMCW transceiver channels and a lens system 903 including one or more optical elements. In some embodiments, the lens system 903 is an embodiment of the lens system 607.

[0085] The SCPA LIDAR chip 905 includes one or more frequency-modulated continuous-wave (FMCW) LIDAR transceivers (e.g., transceiver 104), which are implemented as one or more photonic integrated circuits. The photonic integrated circuit for the transceiver may include an input port, multiple optical antennas, an optical switch, multiple beam splitters, and multiple mixers.

[0086] The input port is configured to receive a frequency-modulated laser signal. The optical switch is configured to switchably couple the input port to the optical antenna, thereby forming an optical path between the input port and the optical antenna. For each optical path from the input port to one of the optical antennas, the beam splitter is coupled along the optical path and is configured to: split a portion of the received laser signal into a local oscillator signal and a transmission signal, where the transmission signal is emitted via the optical antenna and the reflection of the transmission signal is received via the optical antenna as a reflected signal; and output a return signal that is a portion of the reflected signal. For each beam splitter, the mixer is coupled to receive the return signal and the local oscillator signal from the beam splitter, and the mixer is configured to mix the return signal and the local oscillator signal to generate one or more output signals for determining depth information of the field of view of the LIDAR system (also referred to as the field of view of the scanner module 901).

[0087] In some embodiments, the lens system 903 generates a collimated transmission signal that scans the field of view of the scanner module 901 along one or more angular dimensions (e.g., azimuth or elevation). The scanner module 901 has a field of view of 5 degrees or better along one angular dimension. And in embodiments having a two-dimensional arrangement (e.g., a rectangular grid) of optical antennas, the signals from the multiple optical antennas can be scanned in two dimensions within the field of view of the scanner module 901. For example, scanning is performed in a first dimension and a second dimension, and the field of view of the scanner module 901 is 5 degrees or better along the first dimension and 5 degrees or better along the second dimension. The two-dimensional scanning in the above example can be performed by selectively using different coherent pixels.

[0088] The scanner module 901 may also include a scanning mirror 902 to assist in laser beam scanning and / or a quarter-wave plate (QWP) 904 to improve polarization-related sensitivity. In embodiments using the scanning mirror 902, the field of view of the scanner module 901 is 5 degrees or better along a first dimension (scanned via selective use of coherent pixels) and 10 degrees or better along a second dimension (scanned at least in part via movement of the scanning mirror 902). The light source of the LIDAR chip 905 can be directly integrated onto the same chip or coupled via an optical fiber component. As shown, the light source can be a modulated laser source, a CW laser source, an FMCW laser source 907, or another coherent laser source that generates an input signal for coherent LIDAR operation. The FMCW laser source 907 can be further amplified by an optical amplifier 906 to increase the range of the FMCW LIDAR. The optical amplifier 906 can be a semiconductor optical amplifier (SOA) chip or an erbium-doped fiber amplifier (EDFA). The FMCW laser source 907 is controlled by a laser driver circuit 908, which is typically a controllable low-noise current source. The output of the coherent pixels enters an array of transimpedance amplifier (TIA) circuits 911. The on-chip switch is controlled by a switch driver array 910. The FMCW processing engine 909 can be implemented with one or more FPGA, ASIC, or DSP chips, which include the following functionality: SCPA control and calibration logic 915, FMCW LIDAR frame management and point cloud processing 914, multi-channel analog-to-digital converter 916, FMCW LIDAR DSP 912, and FMCW laser chirp control and calibration logic 913. In the case of implementing the SCPA LIDAR chip 905 on a CMOS silicon photonics platform, some or even all of the circuit functionality can be monolithically implemented as a photonic circuit on a single chip. The data output 920 of the FMCW processing engine includes depth information. The depth information can include, for example, three-dimensional position data of a typical LIDAR point cloud and other information that the FMCW LIDAR can measure, such as velocity, reflectivity, etc.

[0089] Figure 9 An example LIDAR system is shown. In alternative configurations, different and / or additional components may be included in the LIDAR system. Additionally, the functionality described in connection with one or more of the components shown in Figure 9 may be distributed among the components in a manner different from that described in connection with Figure 9 . For example, in some embodiments, the SCPA LIDAR chip 905 may be separated from the scanner module 901.

[0090] Figure 10A An example autonomous vehicle 1000 is illustrated in accordance with aspects of the present disclosure, which may include a LIDAR device in Figures 1-9Any LIDAR component. The illustrated autonomous vehicle 1000 includes a sensor array configured to capture one or more objects in the external environment of the autonomous vehicle and generate sensor data related to the captured one or more objects for controlling the operation of the autonomous vehicle 1000. Figure 10A Sensors 1033A, 1033B, 1033C, 1033D, and 1033E are shown. Figure 10B A top view of the autonomous vehicle 1000 is illustrated that includes sensors 1033F, 1033G, 1033H, and 1033I in addition to sensors 1033A, 1033B, 1033C, 1033D, and 1033E. Any one of sensors 1033A, 1033B, 1033C, 1033D, 1033E, 1033F, 1033G, 1033H, and / or 1033I can include a LIDAR device that includes Figures 1-9 Any LIDAR component. Figure 10C A block diagram of an example system 1099 for the autonomous vehicle 1000 is illustrated. For example, the autonomous vehicle 1000 can include a powertrain 1002 that includes a prime mover 1004 powered by an energy source 1006 and capable of powering a driveline 1008. The autonomous vehicle 1000 can also include a control system 1010 that includes a steering control 1012, a powertrain control 1014, and a braking control 1016. The autonomous vehicle 1000 can be implemented as any number of different vehicles, including vehicles capable of transporting people and / or cargo and capable of traveling in a variety of different environments. It should be understood that the above components 1002 - 1016 can vary widely based on the type of vehicle that utilizes these components.

[0091] For example, the embodiments discussed below will focus on wheeled land vehicles such as cars, vans, trucks, or buses. In such embodiments, the prime mover 1004 can include one or more electric motors and / or internal combustion engines (among others). The energy source can include, for example, a fuel system (e.g., providing gasoline, diesel, hydrogen), a battery system, solar panels or other renewable energy sources, and / or a fuel cell system. The drivetrain 1008 can include wheels and / or tires along with a transmission and / or any other mechanical drive components suitable for converting the output of the prime mover 1004 into vehicle motion, as well as one or more brakes configured to controllably stop or slow down the autonomous vehicle 1000 and a direction or steering component suitable for controlling the trajectory of the autonomous vehicle 1000 (e.g., a rack and pinion steering linkage that enables one or more wheels of the autonomous vehicle 1000 to pivot about a generally vertical axis to change the angle of the rotational plane of the wheel relative to the longitudinal axis of the vehicle). In some embodiments, a combination of a powertrain and an energy source can be used (e.g., in the case of an electric / gasoline hybrid vehicle). In some embodiments, multiple electric motors (e.g., dedicated to individual wheels or axles) can be used as the prime mover.

[0092] The direction control 1012 can include one or more actuators and / or sensors for controlling and receiving feedback from the direction or steering component to enable the autonomous vehicle 1000 to follow a desired trajectory. The powertrain control 1014 can be configured to control the output of the powertrain 1002, e.g., control the output power of the prime mover 1004, control the gears of the transmission in the drivetrain 1008, thereby controlling the speed and / or direction of the autonomous vehicle 1000. The brake control 1016 can be configured to control one or more brakes that slow down or stop the autonomous vehicle 1000, e.g., disc or drum brakes coupled to the wheels of the vehicle.

[0093] Other vehicle types, including but not limited to off-road vehicles, all-terrain or tracked vehicles, or construction equipment will necessarily utilize different powertrains, drivetrains, energy sources, direction controls, powertrain controls, and brake controls, as will be understood by those of ordinary skill in the art who benefit from this disclosure. Additionally, in some embodiments, some components can be combined, e.g., where the direction control of the vehicle is primarily handled by changing the output of one or more prime movers. Thus, the embodiments disclosed herein are not limited to the specific application of the techniques described herein to autonomous wheeled land vehicles.

[0094] In the illustrated embodiment, autonomous control of the autonomous vehicle 1000 is implemented in the vehicle control system 1020, which may include one or more processors in the processing logic 1022 and one or more memories 1024, where the processing logic 1022 is configured to execute program code (e.g., instructions 1026) stored in the memory 1024. The processing logic 1022 may include, for example, one or more graphics processing units (GPUs) and / or one or more central processing units (CPUs). The vehicle control system 1020 may be configured to control the powertrain 1002 of the autonomous vehicle 1000 in response to an infrared return beam that is propagated into the external environment of the autonomous vehicle 1000 through one or more waveguides and reflected back to receive the reflection of an infrared transmission beam for a LIDAR pixel.

[0095] Sensors 1033A - 1033I may include various sensors suitable for collecting data from the surrounding environment of the autonomous vehicle for controlling the operation of the autonomous vehicle. For example, sensors 1033A - 1033I can include a RADAR unit 1034, a LIDAR unit 1036, one or more 3D positioning sensors 1038, such as satellite navigation systems, such as GPS, GLONASS, Beidou, Galileo, or a compass. Figures 1-9 The LIDAR components can be included in the interferometer, modulator, and / or resonator of the LIDAR unit 1036. The LIDAR unit 1036 may include, for example, a plurality of LIDAR sensors distributed around the autonomous vehicle 1000. In some embodiments, the one or more 3D positioning sensors 1038 can use satellite signals to determine the position of the vehicle on the earth. Sensors 1033A - 1033I can optionally include one or more ultrasonic sensors, one or more cameras 1040, and / or an inertial measurement unit (IMU) 1042. In some embodiments, the camera 1040 can be a single-image or stereo camera and can record static and / or video images. The camera 1040 may include a complementary metal oxide semiconductor (CMOS) image sensor configured to capture images of one or more objects in the external environment of the autonomous vehicle 1000. The IMU 1042 can include a plurality of gyroscopes and accelerometers capable of detecting the linear and rotational motion of the autonomous vehicle 1000 in three directions. One or more encoders (not shown), such as wheel encoders, can be used to monitor the rotation of one or more wheels of the autonomous vehicle 1000.

[0096] The outputs of sensors 1033A - 1033I can be provided to control subsystem 1050, including positioning subsystem 1052, trajectory subsystem 1056, perception subsystem 1054, and control system interface 1058. The positioning subsystem 1052 is configured to determine the position and orientation (sometimes also referred to as "pose") of the autonomous vehicle 1000 in its surrounding environment, and typically within a specific geographic area. The position of the autonomous vehicle can be compared with the positions of additional vehicles in the same environment as part of generating labeled autonomous vehicle data. The perception subsystem 1054 can be configured to detect, track, classify, and / or determine objects in the surrounding environment of the autonomous vehicle 1000. The trajectory subsystem 1056 is configured to generate a trajectory of the autonomous vehicle 1000 within a specific time frame given a desired destination, as well as static and moving objects in the environment. Machine learning models according to several embodiments can be used to generate vehicle trajectories. The control system interface 1058 is configured to communicate with the control system 1010 to implement the trajectory of the autonomous vehicle 1000. In some embodiments, machine learning models can be used to control the autonomous vehicle to achieve the planned trajectory.

[0097] It should be understood that the set of components shown for the vehicle control system 1020 in Figure 10C is merely exemplary in nature. Individual sensors may be omitted in some embodiments. In some embodiments, Figure 10C the different types of sensors shown in are used for redundancy and / or for covering different regions in the surrounding environment of the autonomous vehicle. In some embodiments, different types and / or combinations of control subsystems may be used. Additionally, although subsystems 1052 - 1058 are shown as separate from the processing logic 1022 and the memory 1024, it should be understood that in some embodiments, some or all of the functionality of subsystems 1052 - 1058 can be implemented as program code such as instructions 1026 residing in the memory 1024 and executed by the processing logic 1022, and these subsystems 1052 - 1058 can in some cases use the same (multiple) processors and / or memory for implementation. The subsystems in some embodiments can be implemented at least in part using various dedicated circuit logics, various processors, various field programmable gate arrays ("FPGAs"), various application specific integrated circuits ("ASICs"), various real - time controllers, etc. As described above, multiple subsystems can utilize circuits, processors, sensors, and / or other components. Additionally, the various components in the vehicle control system 1020 can be networked in various ways.

[0098] In some embodiments, different architectures, including various combinations of software, hardware, circuit logic, sensors, and networks can be used to implement Figure 10CThe various components shown in [figure]. For example, each processor may be implemented as a microprocessor, and each memory may represent a random access memory ("RAM") device including main storage, as well as any supplementary levels of memory such as cache memory, non-volatile or backup memory (e.g., programmable memory or flash memory), or read-only memory. Additionally, each memory may be considered to include memory physically located elsewhere in the autonomous vehicle 1000, such as any cache memory in the processor, and any storage capacity used as virtual memory, such as that stored on a mass storage device or another computer controller. Figure 10C The processing logic 1022 shown in [figure] or completely separate processing logic may be used to implement additional functionality in the autonomous vehicle 1000 beyond autonomous control purposes, such as controlling an entertainment system, operating doors, lights, or convenience features.

[0099] In addition, for additional storage, the autonomous vehicle 1000 may also include one or more mass storage devices, such as removable disk drives, hard disk drives, direct access storage devices ("DASD"), optical drives (e.g., CD drives, DVD drives), solid state storage drives ("SSD"), network attached storage, storage area networks, and / or tape drives, etc. Additionally, the autonomous vehicle 1000 may include a user interface 1064 to enable the autonomous vehicle 1000 to receive multiple inputs from passengers and generate outputs for passengers, such as one or more displays, touchscreens, voice and / or gesture interfaces, buttons, and other tactile controls. In some embodiments, inputs from passengers may be received via another computer or electronic device, such as via an application on a mobile device or via a web interface.

[0100] In some embodiments, the autonomous vehicle 1000 may include one or more network interfaces, such as network interface 1062, suitable for communicating with one or more networks 1070 (e.g., local area network ("LAN"), wide area network ("WAN"), wireless network, and / or the Internet, etc.) to allow information communication with other computers and electronic devices (including, for example, central services such as cloud services) from which the autonomous vehicle 1000 receives environmental and other data for its autonomous control. In some embodiments, data collected by one or more sensors 1033A - 1033I can be uploaded via the network 1070 to a computing system 1072 for additional processing. In such embodiments, a timestamp can be associated with each instance of vehicle data prior to uploading.

[0101] Figure 10CThe processing logic 1022 shown in [FIGURE] and the various additional controllers and subsystems disclosed herein generally operate under the control of an operating system and execute or otherwise rely on various computer software applications, components, programs, objects, modules, or data structures, as may be described in more detail below. Additionally, various applications, components, programs, objects, or modules may also be executed on one or more processors in another computer coupled to the autonomous vehicle 1000 via the network 1070, e.g., in a distributed, cloud-based, or client-server computing environment, whereby the processing required to implement the computer program functionality may be distributed across multiple computers and / or services via the network.

[0102] The routines executed to implement the various embodiments described herein, whether as part of an operating system, a specific application, component, program, object, module, or sequence of instructions, or even a subset thereof, will be referred to herein as "program code". Program code typically includes one or more instructions that reside at various times in various memory and storage devices and, when read and executed by one or more processors, perform the steps necessary to implement the steps or elements embodying the various aspects of the present invention. Additionally, while the embodiments have been and may hereinafter be described in the context of full-featured computers and systems, it should be understood that the various embodiments described herein are capable of being distributed as a program product in a variety of forms and that the embodiments can be implemented regardless of the particular type of computer-readable medium used to actually effectuate the distribution. Examples of computer-readable media include tangible, non-transitory media such as volatile and non-volatile storage devices, floppy disks and other removable disks, solid state drives, hard disk drives, magnetic tape, and optical discs (e.g., CD-ROM, DVD), among others.

[0103] Furthermore, the various program code described below may be identified based on the application programs implemented in their particular embodiments. However, it should be understood that any specific program nomenclature used below is for convenience only and thus the present invention should not be limited to use in any particular application identified and / or implied by such nomenclature. Additionally, considering that there are typically myriad ways to organize computer programs into routines, procedures, methods, modules, objects, etc., and various ways to distribute program functionality among the various software layers resident in a typical computer (e.g., operating system, libraries, APIs, applications, applets), it should be understood that the present invention is not limited to the particular organization and distribution of program functionality described herein.

[0104] Those skilled in the art who benefit from this disclosure will recognize that in Figure 10CThe exemplary environments shown are not intended to limit the embodiments disclosed herein. In fact, those skilled in the art will recognize that other alternative hardware and / or software environments may be used without departing from the scope of the embodiments disclosed herein.

[0105] In embodiments of the present disclosure, visible light may be defined as having a wavelength range of approximately 380 nm - 700 nm. Non-visible light may be defined as light having a wavelength outside the visible light range, such as ultraviolet light and infrared light. Infrared light having a wavelength range of approximately 700 nm - 1 mm includes near-infrared light. In aspects of the present disclosure, near-infrared light may be defined as having a wavelength range of approximately 700 nm - 1.6 μm.

[0106] In aspects of the present disclosure, the term "transparent" may be defined as having a light transmittance greater than 90%. In some aspects, the term "transparent" may be defined as a material having a visible light transmittance greater than 90%.

[0107] The term "processing logic" in the present disclosure may include one or more processors, microprocessors, multi-core processors, application-specific integrated circuits (ASICs), and / or field-programmable gate arrays (FPGAs) to perform the operations disclosed herein. In some embodiments, a memory (not shown) is integrated into the processing logic to store instructions to perform operations and / or store data. The processing logic may also include analog or digital circuits to perform operations in accordance with embodiments of the present disclosure.

[0108] One or more "memories" described in the present disclosure may include one or more volatile or non-volatile memory architectures. One or more "memories" may be removable and non-removable media implemented by any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Example memory technologies may include RAM, ROM, EEPROM, flash memory, CD-ROM, digital versatile disk (DVD), high-definition multimedia / data storage disk, or other optical storage, magnetic cassette tape, tape, disk storage, or other magnetic storage devices, or any other non-transitory medium capable of storing information for access by a computing device.

[0109] A network may include any network or network system, such as but not limited to the following: peer-to-peer network; local area network (LAN); wide area network (WAN); public network such as the Internet; private network; cellular network; wireless network; wired network; wireless and wired combined network; and satellite network.

[0110] A communication channel may include one or more wired or wireless communications using the IEEE 802.11 protocol, Bluetooth, SPI (Serial Peripheral Interface), I2C (Inter-Integrated Circuit), USB (Universal Serial Port), CAN (Controller Area Network), cellular data protocols (such as 3G, 4G, LTE, 5G), optical communication networks, Internet Service Providers (ISPs), peer-to-peer networks, Local Area Networks (LANs), Wide Area Networks (WANs), public networks (such as the "Internet"), private networks, satellite networks, or other networks, or be routed through any of the foregoing.

[0111] Computing devices may include desktop computers, laptop computers, tablet computers, phablets, smartphones, feature phones, server computers, etc. Server computers may be located remotely in a data center or stored locally.

[0112] The processes explained above are described in terms of computer software and hardware. The described techniques may constitute machine-executable instructions embodied in a tangible or non-transitory machine (e.g., a computer) readable storage medium, which when executed by a machine will cause the machine to perform the described operations. Additionally, these processes may be embodied in hardware, such as an Application Specific Integrated Circuit ("ASIC") or others.

[0113] A tangible non-transitory machine readable storage medium includes any mechanism that provides information in a form accessible by a machine (e.g., a computer, network device, personal digital assistant, manufacturing tool, any device having one or more sets of processors, etc.). For example, machine readable storage media include recordable / non-recordable media (e.g., read only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash devices, etc.).

[0114] The foregoing description of exemplary embodiments of the invention, including what is described in the abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific embodiments and examples of the invention are described herein for illustrative purposes, various modifications may be made within the scope of the invention, as will be recognized by those skilled in the relevant art.

[0115] These modifications to the invention can be made in light of the above detailed description. The terms used in the appended claims should not be construed as limiting the invention to the specific embodiments disclosed in the specification. Instead, the scope of the invention will be determined entirely by the appended claims, which will be interpreted according to established principles of claim interpretation.

Claims

1. A light detection and ranging (LIDAR) sensor system, comprising: A transceiver configured to receive a transmission signal, wherein the transceiver includes: A plurality of optical antenna arrays; and An active optical switch including an input configured to receive the transmission signal and a specific number of output channels respectively coupled to the plurality of optical antenna arrays, wherein the active optical switch is configured to selectively provide the transmission signal to the plurality of optical antenna arrays by coupling the transmission signal to at least one selected optical antenna array among the plurality of optical antenna arrays one by one during a scan period of the transceiver; and Wherein at least three of the plurality of optical antenna arrays respectively include: A specific number of optical antennas arranged in a two-dimensional configuration; and A splitter coupled to the specific number of optical antennas and configured to separately provide the transmission signal to each of the specific number of optical antennas, wherein the splitter is configured to receive the transmission signal from an output channel of a specific number of output channels of the active optical switch, and wherein the splitter includes a plurality of active splitters configured to evenly distribute the transmission signal to a specific number of communication channels corresponding to the specific number of optical antennas.

2. The LIDAR sensor system according to claim 1, wherein, The specific number of optical antennas corresponds to a specific number of coherent pixels, and a corresponding coherent pixel among the specific number of coherent pixels is configured to correspondingly provide a transmission signal to a corresponding optical antenna among the specific number of optical antennas and receive a return signal from the corresponding optical antenna.

3. The LIDAR sensor system according to claim 1, wherein, The splitter is configured to enable the transmission signal to be simultaneously transmitted to the specific number of communication channels and to be simultaneously transmitted from the specific number of optical antennas in at least one selected optical antenna array.

4. The LIDAR sensor system according to claim 1, wherein, The active optical switch includes at least one of the following: a binary tree switch, an array of micro-ring resonators, and an array of micro-electro-mechanical system (MEMS) switches.

5. The LIDAR sensor system according to claim 1, further comprising an additional optical splitter configured to receive an input signal, wherein, Configured to split the input signal into the transmission signal and a local oscillator signal.

6. The LIDAR sensor system according to claim 5, wherein: The input signal is a modulated laser signal; and The active splitter includes an active splitter that selectively couples the modulated laser signal to only one of the plurality of optical antenna arrays at a time.

7. The LIDAR sensor system according to claim 5, wherein: The input signal is a frequency-modulated continuous wave (FMCW) laser signal; and The active splitter includes an active splitter that selectively couples the FMCW laser signal to only one of the plurality of optical antenna arrays at a time.

8. The LIDAR sensor system according to claim 3, wherein, The active optical switch is configured to optically couple the transmission signal to at least one of the plurality of optical antenna arrays one by one during a scan period of the transceiver to illuminate one or more specific parts of a scene in a field of view of the LIDAR sensor system.

9. The LIDAR sensor system according to claim 5, further comprising a local oscillator network coupled to the additional optical splitter and configured to receive the local oscillator signal from the additional optical splitter, wherein, The local oscillator network is configured to selectively split the local oscillator signal into a plurality of local oscillator signals for the plurality of optical antenna arrays.

10. The LIDAR sensor system according to claim 9, wherein, The local oscillator network includes: A plurality of optical splitters configured to provide the plurality of local oscillator signals to the plurality of optical antenna arrays; and An additional optical switch coupled to the plurality of optical splitters and configured to selectively provide a portion of the local oscillator signals to at least one of the plurality of optical splitters of the local oscillator network.

11. The LIDAR sensor system according to claim 9, further comprising an optical combiner coupled to at least one of the specific number of optical antennas to receive the return signal, wherein, The optical combiner is configured to combine the return signal with the local oscillator signal and provide a combined output signal.

12. The LIDAR sensor system according to claim 11, wherein, Corresponding pixels of the optical antennas among the specific number of optical antennas include a plurality of photodiodes configured to convert the combined output signal into an electrical signal representing a LIDAR beat.

13. The LIDAR sensor system according to claim 1, wherein, At least three of the plurality of optical antenna arrays include output signal buses, wherein a specific number of optical antennas of a first optical antenna array among the plurality of optical antenna arrays share the output signal bus with a second optical antenna array among the plurality of optical antenna arrays.

14. The LIDAR sensor system according to claim 13, wherein, The output signal bus includes electrical signal lines for in-phase signals and quadrature signals from each of the specific number of optical antennas.

15. An integrated chip for a light detection and ranging (LIDAR) sensor, the integrated chip comprising: A light source configured to generate an input signal; An optical splitter configured to receive the input signal, wherein the optical splitter is configured to split the input signal into a transmission signal and a local oscillator signal; A transceiver coupled to the optical splitter to receive the transmission signal, wherein the transceiver includes: A plurality of optical antenna arrays; and An active optical switch including an input configured to receive the transmission signal and a specific number of output channels respectively coupled to the plurality of optical antenna arrays, wherein the active optical switch is configured to selectively provide the transmission signal to the plurality of optical antenna arrays by coupling the transmission signal to at least one selected optical antenna array among the plurality of optical antenna arrays one at a time during a scan period of the transceiver; and Wherein at least three of the plurality of optical antenna arrays respectively include: A specific number of optical antennas arranged in a two-dimensional configuration; and An optical splitter coupled to the specific number of optical antennas and configured to individually provide the transmission signal to each of the specific number of optical antennas, wherein the optical splitter is configured to receive the transmission signal from an output channel of a specific number of output channels of the active optical switch, and wherein the optical splitter includes a plurality of active optical splitters configured to evenly distribute the transmission signal to a specific number of communication channels corresponding to the specific number of optical antennas.

16. The LIDAR sensor chip according to claim 15, further comprising a lens, wherein, The transceiver is optically coupled to the lens to scan the field of view block of the lens.

17. The LIDAR sensor chip according to claim 15, further comprising: A processing engine configured to receive a LIDAR return signal from the transceiver and configured to generate a LIDAR data frame based on the LIDAR return signal.

18. An autonomous vehicle, comprising: A light detection and ranging (LIDAR) sensor, the LIDAR sensor including: A light source configured to generate an input signal; A splitter configured to receive the input signal, wherein the splitter is configured to split the input signal into a transmission signal and a local oscillator signal; and A transceiver configured to receive the transmission signal, wherein the transceiver includes: A plurality of optical antenna arrays; and An active optical switch including inputs configured to receive the input of the transmission signal and a specific number of output channels respectively coupled to the plurality of optical antenna arrays, wherein the active optical switch is configured to selectively provide the transmission signal to the plurality of optical antenna arrays by coupling the transmission signal to at least one selected optical antenna array of the plurality of optical antenna arrays one at a time during a scan period of the transceiver; and Wherein at least three of the plurality of optical antenna arrays each include: A specific number of optical antennas arranged in a two-dimensional configuration; and A splitter coupled to the specific number of optical antennas and configured to individually provide the transmission signal to each of the specific number of optical antennas, wherein the splitter is configured to receive the transmission signal from an output channel of the specific number of output channels of the active optical switch, and wherein the splitter includes a plurality of active splitters configured to evenly distribute the transmission signal to a specific number of communication channels corresponding to the specific number of optical antennas.

19. The autonomous vehicle according to claim 18, further comprising a lens, wherein, The transceiver is optically coupled to the lens to provide a horizontal scan of the operating environment of the autonomous vehicle.

20. The autonomous vehicle according to claim 18, further comprising: A processing engine configured to receive LIDAR return signals from the transceiver and configured to generate a point cloud representation of the operating environment of the autonomous vehicle based at least in part on the LIDAR return signals.

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